will show you the mail headers it would have generated (including subject lines, To: and Cc: fields).
git format-patch -o<tempdir> <committish>
will create a separate mail-like file for each patch in <tempdir>. Finally,
git format-patch --stdout <committish> > foo.mbox
will (I think) generate something which something capable of reading mbox'es should be able to read. (The latter I may be remembering incorrectly, but worth giving a try.)
